PCI: iproc: Update PCIe device tree bindings

- phys: phandle of the PCIe PHY device

- phy-names: must be "pcie-phy"

- brcm,pcie-ob: Some iProc SoCs do not have the outbound address mapping done

by the ASIC after power on reset. In this case, SW needs to configure it

If the brcm,pcie-ob property is present, the following properties become

effective:

Required:

- brcm,pcie-ob-axi-offset: The offset from the AXI address to the internal

address used by the iProc PCIe core (not the PCIe address)

- brcm,pcie-ob-window-size: The outbound address mapping window size (in MB)

Optional:

- brcm,pcie-ob-oarr-size: Some iProc SoCs need the OARR size bit to be set to

increase the outbound window size

Example:

	pcie0: pcie@18012000 {

		compatible = "brcm,iproc-pcie";

		phys = <&phy 0 5>;

		phy-names = "pcie-phy";

		brcm,pcie-ob;

		brcm,pcie-ob-oarr-size;

		brcm,pcie-ob-axi-offset = <0x00000000>;

		brcm,pcie-ob-window-size = <256>;

	};

	pcie1: pcie@18013000 {